'Serious concern': Pregnant people often exposed to cancer-causing chemicals

Key takeaways

• In a recent study, almost every pregnant participant was exposed to cyanuric acid and melamine, which can be found in common household products such as disinfectants and pesticides.
• Researchers found higher levels of the chemicals in people from underrepresented communities.
• Many of the compounds that researchers found are also associated with toxicities, and exposure during the prenatal period could affect the fetus.

Pregnant people are often exposed to dangerous chemicals commonly found in household products, a recent study showed. Researchers said the data also revealed racial and ethnic disparities and provide “important public health implications.”

Giehae Choi, MPH, PhD, a postdoctoral fellow at the Johns Hopkins Bloomberg School of Public Health, and colleagues detected cyanuric acid, melamine and nine aromatic amines in more than 50% of participants’ urine samples, and a combination of cyanuric acid and melamine in even more samples.

“These chemicals are of serious concern due to their links to cancer and developmental toxicity, yet they are not routinely monitored in the United States,” Tracey J. Woodruff, PhD, a professor of obstetrics, gynecology and reproductive medicine at the University of California, San Francisco, and co-senior author of the study, said in a press release.

Aromatic amines are commonly found in tobacco smoke, diesel exhaust, paint, tattoo ink, hair dye and mascara, according to the release. Cyanuric acid is used as a cleaning solvent in swimming pools, a plastic stabilizer and a disinfectant, while melamine is commonly found in flooring, plastics, dishware and pesticides.

The dangers of melamine contamination are well-documented. It was recognized as a kidney toxicant after reports of baby formula and pet food poisoning in 2004, 2007 and 2008, which led to several deaths, according to the release.

Because “many of these compounds with widespread exposures also have known toxicities,” the researchers wrote that there is a “critical need to identify intervention approaches in addition to monitoring exposures and health effects in the population.” Being exposed during the prenatal period, they wrote, could “increase the risk for developmental effects in the children due to unique or heightened periods of developmental susceptibility and the potential for maternal-fetal transfer via the placenta and breastmilk.”

The researchers used new methods to measure 45 chemicals that are associated with health risks. They used urine samples from “a small but diverse group” of 171 women from Puerto Rico, New York, New Hampshire, Georgia, Illinois and California, according to the release. Of the participants, about 40% were Hispanic, 34% were white, 20% were Black and 4% were Asian.

The study, published in Chemosphere, revealed that every sample except for one had detectable concentrations of both cyanuric acid and melamine, a finding that troubled the researchers because of the potential effects on kidneys.

“The ubiquitous detection of both melamine and cyanuric acid in our pregnant population is concerning since kidney toxicities have been reported at varying exposure levels and there are potentials for developmental effects,” the researchers wrote. “Kidney effects, ranging from symptomatic or asymptomatic urolithiasis to acute renal failure and urinary tract obstruction, have been observed in children with chronic histories of melamine-contaminated formula consumption.”

In estimating the exposure levels “and exploring their sociodemographic predictors,” the researchers determined that, even after adjusting for other variables, the chemical exposure levels varied by race and ethnicity.

For instance, four types of aromatic amines were found in nearly all participants, though higher levels were associated with those who were Hispanic, Black or exposed to tobacco smoke. Compared with white women, the researchers noted that exposure to 3,4-dichloroaniline was much higher — more than 100% — among Black (136% difference; 95% CI, 35-311) and Hispanic (149% difference; 95% CI, 17-431) women.

The authors wrote that they were “unable to assess specific exposure factors that may help to explain such differences,” and that future research is necessary to further examine factors that contribute to exposure differences.

“It’s disconcerting that we continue to find higher levels of many of these harmful chemicals in people of color,” Jessie Buckley, PhD, an associate professor at Johns Hopkins Bloomberg School of Public Health and co-senior author, said in the release.

The researchers concluded that a larger follow-up study is needed to “better characterize exposures across the U.S. during a critical period of development and further assess influential predictors and demographic differences that we characterized in this initial study.”

References:

• Choi G, et al. Chemosphere. 2022;doi:10.1016/j.chemosphere.2022.135599.
• Study reveals pregnant women are exposed to cancer-causing chemicals in dishware, hair coloring, plastics, and pesticides. https://www.ucsf.edu/news/2022/08/423586/pregnant-women-exposed-cancer-causing-chemicals-dishware-hair-coloring-plastics. Published Aug. 29, 2022. Accessed Sept. 6, 2022.